Tumor necrosis factor-xcex1, or TNFxcex1, is a cytokine which is released primarily by mononuclear phagocytes in response to a number immunostimulators. It is a key proinflammatory cytokine in the inflammation cascade causing the production and/or release of other cytokines and agents. When administered to animals or humans, it causes inflammation, fever, cardiovascular effects, hemorrhage, coagulation, and acute phase responses similar to those seen during acute infections and shock states. Excessive or unregulated TNFxcex1 production thus has been implicated in a number of disease conditions. These include endotoxemia and/or toxic shock syndrome {Tracey et al., Nature 330, 662-664 (1987) and Hinshaw et al., Circ. Shock 30, 279-292 (1990)}; cachexia {Dezube et al., Lancet, 335 (8690), 662 (1990)} and Adult Respiratory Distress Syndrome (ARDS) where TNFxcex1 concentration in excess of 12,000 pg/mL have been detected in pulmonary aspirates from ARDS patients {Millar et al., Lancet 2(8665), 712-714 (1989)}. Systemic infusion of recombinant TNFxcex1 also resulted in changes typically seen in ARDS {Ferrai-Baliviera et al., Arch. Surg. 124(12), 1400-1405 (1989)}.
TNFxcex1 appears to be involved in bone resorption diseases, including arthritis. When activated, leukocytes will produce bone-resorption, an activity to which the data suggest TNFxcex1 contributes. {Bertolini et al., Nature 319, 516-518 (1986) and Johnson et al, Endocrinology 124(3), 1424-1427 (1989).} TNFxcex1 also has been shown to stimulate bone resorption and inhibit bone formation in vitro and in vivo through stimulation of osteoclast formation and activation combined with inhibition of osteoblast function. Although TNFxcex1 may be involved in many bone resorption diseases, including arthritis, the most compelling link with disease is the association between production of TNFxcex1 by tumor or host tissues and malignancy associated hypercalcemia {Calci. Tissue Int. (US) 46(Suppl.), S3-10 (1990)}. In Graft versus Host Reaction, increased serum TNFxcex1 levels have been associated with major complication following acute allogenic bone marrow transplants {Holler et al., Blood, 75(4), 1011-1016 (1990)}.
Cerebral malaria is a lethal hyperacute neurological syndrome associated with high blood levels of TNFxcex1 and the most severe complication occurring in malaria patients. Levels of serum TNFxcex1 correlated directly with the severity of disease and the prognosis in patients with acute malaria attacks {Grau et al., N. Engl. J. Med. 320(24), 1586-1591 (1989)}.
Macrophage-induced angiogenesis is known to be mediated by TNFxcex1. Leibovich et al. {Nature, 329, 630-632 (1987)} showed TNFxcex1 induces in vivo capillary blood vessel formation in the rat cornea and the developing chick chorioallantoic membranes at very low doses and suggest TNFxcex1 is a candidate for inducing angiogenesis in inflammation, wound repair, and tumor growth. TNFxcex1 production also has been associated with cancerous conditions, particularly induced tumors {Ching et al., Brit. J. Cancer, (1955) 72, 339-343, and Koch, Progress in Medicinal Chemistry, 22, 166-242 (1985)}.
TNFxcex1 also plays a role in the area of chronic pulmonary inflammatory diseases. The deposition of silica particles leads to silicosis, a disease of progressive respiratory failure caused by a fibrotic reaction. Antibody to TNFxcex1 completely blocked the silica-induced lung fibrosis in mice {Pignet et al., Nature, 344, 245-247 (1990)}. High levels of TNFxcex1 production (in the serum and in isolated macrophages) have been demonstrated in animal models of silica and asbestos induced fibrosis {Bissonnette et al., Inflammation 13(3), 329-339 (1989)}. Alveolar macrophages from pulmonary sarcoidosis patients have also been found to spontaneously release massive quantities of TNFxcex1 as compared with macrophages from normal donors {Baughman et al., J. Lab. Clin. Med. 115(1), 36-42 (1990)}.
TNFxcex1 is also implicated in the inflammatory response which follows reperfusion, called reperfusion injury, and is a major cause of tissue damage after loss of blood flow {Vedder et al., PNAS 87, 2643-2646 (1990)}. TNFxcex1 also alters the properties of endothelial cells and has various pro-coagulant activities, such as producing an increase in tissue factor pro-coagulant activity and suppression of the anticoagulant protein C pathway as well as down-regulating the expression of thrombomodulin {Sherry et al., J. Cell Biol. 107, 1269-1277 (1988)}. TNFxcex1 has pro-inflammatory activities which together with its early production (during the initial stage of an inflammatory event) make it a likely mediator of tissue injury in several important disorders including but not limited to, myocardial infarction, stroke and circulatory shock. Of specific importance may be TNFxcex1-induced expression of adhesion molecules, such as intercellular adhesion molecule (ICAM) or endothelial leukocyte adhesion molecule (ELAM) on endothelial cells {Munro et al., Am. J. Path. 135(1), 121-132 (1989)}.
TNFxcex1 blockage with monoclonal anti-TNFxcex1 antibodies has been shown to be beneficial in rheumatoid arthritis {Elliot et al., Int. J. Pharmac. 1995 17(2), 141-145}. High levels of TNFxcex1 are associated with Crohn""s disease {von Dullemen et al., Gastroenterology, 1995 109(1), 129-135} and clinical benefit has been achieved with TNFxcex1 antibody treatment.
Moreover, it now is known that TNFxcex1 is a potent activator of retrovirus replication including activation of HIV-1. {Duh et al., Proc. Nat. Acad. Sci. 86, 5974-5978 (1989); Poll et al., Proc. Nat. Acad. Sci. 87, 782-785 (1990); Monto et al., Blood 79, 2670 (1990); Clouse et al., J. Immunol. 142, 431-438 (1989); Poll et al., AIDS Res. Hum. Retrovirus, 191-197 (1992)}. AIDS results from the infection of T lymphocytes with Human Immunodeficiency Virus (HIV). At least three types or strains of HIV have been identified, i.e., HIV-1, HIV-2 and HIV-3. As a consequence of HIV infection, T-cell mediated immunity is impaired and infected individuals manifest severe opportunistic infections and/or unusual neoplasms. HIV entry into the T lymphocyte requires T lymphocyte activation. Other viruses, such as HIV-1, HIV-2 infect T lymphocytes after T cell activation and such virus protein expression and/or replication is mediated or maintained by such T cell activation. Once an activated T lymphocyte is infected with HIV, the T lymphocyte must continue to be maintained in an activated state to permit HIV gene expression and/or HIV replication. Cytokines, specifically TNFxcex1, are implicated in activated T-cell mediated HIV protein expression and/or virus replication by playing a role in maintaining T lymphocyte activation. Therefore, interference with cytokine activity such as by prevention or inhibition of cytokine production, notably TNFxcex1, in an HIV-infected individual assists in limiting the maintenance of T lymphocyte caused by HIV infection.
Monocytes, macrophages, and related cells, such as kupffer and glial cells, also have been implicated in maintenance of the HIV infection. These cells, like T cells, are targets for viral replication and the level of viral replication is dependent upon the activation state of the cells. {Rosenberg et al., The Immunopathogenesis of HIV Infection, Advances in Immunology, 57 (1989)}. Cytokines, such as TNFxcex1, have been shown to activate HIV replication in monocytes and/or macrophages {Poli et al., Proc. Natl. Acad. Sci., 87, 782-784 (1990)}, therefore, prevention or inhibition of cytokine production or activity aids in limiting HIV progression for T cells. Additional studies have identified TNFxcex1 as a common factor in the activation of HIV in vitro and has provided a clear mechanism of action via a nuclear regulatory protein found in the cytoplasm of cells (Osborn, et al., PNAS 86 2336-2340). This evidence suggests that a reduction of TNFxcex1 synthesis may have an antiviral effect in HIV infections, by reducing the transcription and thus virus production.
AIDS viral replication of latent HIV in T cell and macrophage lines can be induced by TNFxcex1 {Folks et al., PNAS 86, 2365-2368 (1989)}. A molecular mechanism for the virus inducing activity is suggested by TNFxcex1""s ability to activate a gene regulatory protein (NFxcexaB) found in the cytoplasm of cells, which promotes HIV replication through binding to a viral regulatory gene sequence (LTR) {Osborn et al., PNAS 86, 2336-2340 (1989)}. TNFxcex1 in AIDS associated cachexia is suggested by elevated serum TNFxcex1 and high levels of spontaneous TNFxcex1 production in peripheral blood monocytes from patients {Wright et al., J. Immunol. 141(1), 99-104 (1988)}. TNFxcex1 has been implicated in various roles with other viral infections, such as the cytomegalia virus (CMV), influenza virus, adenovirus, and the herpes family of viruses for similar reasons as those noted.
The nuclear factor xcexaB (NFxcexaB) is a pleiotropic transcriptional activator (Lenardo, et al., Cell 1989, 58, 227-29). NFxcexaB has been implicated as a transcriptional activator in a variety of disease and inflammatory states and is thought to regulate cytokine levels including but not limited to TNFxcex1 and also to be an activator of HIV transcription (Dbaibo, et al., J. Biol. Chem. 1993, 17762-66; Duh et al., Proc. Natl. Acad. Sci. 1989, 86, 5974-78; Bachelerie et al., Nature 1991, 350, 709-12; Boswas et al., J. Acquired Immune Deficiency Syndrome 1993, 6, 778-786; Suzuki et al., Biochem. And Biophys. Res. Comm. 1993, 193, 277-83; Suzuki et al., Biochem. And Biophys. Res Comm. 1992, 189, 1709-15; Suzuki et al., Biochem. Mol. Bio. Int. 1993, 31(4), 693-700; Shakhov et al., Proc. Natl. Acad. Sci. USA 1990, 171, 35-47; and Staal et al., Proc. Natl. Acad. Sci. USA 1990, 87, 9943-47). Thus, inhibition of NFxcexaB binding can regulate transcription of cytokine gene(s) and through this modulation and other mechanisms be useful in the inhibition of a multitude of disease states. The compounds described herein can inhibit the action of NFxcexaB in the nucleus and thus are useful in the treatment of a variety of diseases including but not limited to rheumatoid arthritis, rheumatoid spondylitis, osteoarthritis, other arthritic conditions, septic shock, septis, endotoxic shock, graft versus host disease, wasting, Crohn""s disease, ulcerative colitis, multiple sclerosis, systemic lupus erythrematosis, ENL in leprosy, HIV, AIDS, and opportunistic infections in AIDS. TNFxcex1 and NFxcexaB levels are influenced by a reciprocal feedback loop. As noted above, the compounds of the present invention affect the levels of both TNFxcex1 and NFxcexaB.
Many cellular functions are mediated by levels of adenosine 3xe2x80x2,5xe2x80x2-cyclic monophosphate (cAMP). Such cellular functions can contribute to inflammatory conditions and diseases including asthma, inflammation, and other conditions (Lowe and Cheng, Drugs of the Future, 17(9), 799-807, 1992). It has been shown that the elevation of cAMP in inflammatory leukocytes inhibits their activation and the subsequent release of inflammatory mediators, including TNFxcex1 and NFxcexaB. Increased levels of cAMP also leads to the relaxation of airway smooth muscle. Phosphodiesterases control the level of cAMP through hydrolysis and inhibitors of phosphodiesterases have been shown to increase cAMP levels.
Decreasing TNFxcex1 levels and/or increasing cAMP levels thus constitutes a valuable therapeutic strategy for the treatment of many inflammatory, infectious, immunological or malignant diseases. These include but are not restricted to septic shock, sepsis, endotoxic shock, hemodynamic shock and sepsis syndrome, post ischemic reperfusion injury, malaria, mycobacterial infection, meningitis, psoriasis, congestive heart failure, fibrotic disease, cachexia, graft rejection, cancer, autoimmune disease, opportunistic infections in AIDS, rheumatoid arthritis, rheumatoid spondylitis, osteoarthritis, other arthritic conditions, Crohn""s disease, ulcerative colitis, multiple sclerosis, systemic lupus erythrematosis, ENL in leprosy, radiation damage, and hyperoxic alveolar injury. Prior efforts directed to the suppression of the effects of TNFxcex1 have ranged from the utilization of steroids such as dexamethasone and prednisolone to the use of both polyclonal and monoclonal antibodies {Beutler et al., Science 234,470-474 (1985); WO 92/11383}.
The present invention is based on the discovery that certain classes of non-polypeptide compounds more fully described herein decrease the levels of TNFxcex1, increase cAMP levels, and inhibit inflammatory cytokines. The present invention thus relates to 1-oxo- and 1,3-dioxo-2-(2,6-dioxopiperidin-3-yl)isoindolines substituted in the 4-position of the isoindoline ring and optionally further substituted in the 3-position of the 2,6-dioxopiperidine ring, the method of reducing levels of tumor necrosis factor xcex1 and other inflammatory cytokines in a mammal through the administration of such derivatives, and pharmaceutical compositions containing such derivatives.
In particular, the invention pertains to
(a) a 2-(2,6-dioxopiperidin-3-yl)-isoindoline of the formula: 
xe2x80x83in which
Y is oxygen or H2,
a first of R1 and R2 is halo, alkyl, alkoxy, alkylamino, dialkylamino, cyano, or carbamoyl, the second of R1 and R2, independently of the first, is hydrogen, halo, alkyl, alkoxy, alkylamino, dialkylamino, cyano, or carbamoyl, and
R3 is hydrogen, alkyl, or benzyl, and
(b) the acid addition salts of said 2-(2,6-dioxopiperidin-3-yl)-isoindolines which contain a nitrogen atom capable of being protonated.
Unless otherwise defined, the term alkyl denotes a univalent saturated branched or straight hydrocarbon chain containing from 1 to 4 carbon atoms. Representative of such alkyl groups are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, and tert-butyl. Alkoxy refers to an alkyl group bound to the remainder of the molecule through an ethereal oxygen atom. Representative of such alkoxy groups are methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, and tert-butoxy.
Halo includes bromo, chloro, fluoro, and iodo.
The compounds of Formula I are used, under the supervision of qualified professionals, to inhibit the undesirable effects of TNFxcex1 and other inflammatory cytokines including the interleukins IL-1, IL-6, and IL-12. The compounds can be administered orally, rectally, or parenterally, alone or in combination with other therapeutic agents including antibiotics, steroids, chemotherapeutic agents, etc., to a mammal in need of treatment; e.g., in the treatment of cancers, rheumatoid arthritis, inflammatory bowel disease, muscular dystrophy, Crohn""s disease, etc.
The compounds of the present invention also can be used topically in the treatment or prophylaxis of disease states mediated or exacerbated by excessive TNFxcex1 production, respectively, such as viral infections, such as those caused by the herpes viruses, or viral conjunctivitis, psoriasis, atopic dermatitis, etc.
The compounds also can be used in the veterinary treatment of mammals other than humans in need of prevention or inhibition of TNFxcex1 production. TNFxcex1 mediated diseases for treatment, therapeutically or prophylactically, in animals include disease states such as those noted above, but in particular viral infections. Examples include feline immunodeficiency virus, equine infectious anaemia virus, caprine arthritis virus, visna virus, and maedi virus, as well as other lentiviruses.
The compounds of Formula I are readily prepared through a number of routes. In a first embodiment, an anhydride or lactone is allowed to react with a 3-amino-2,6-dioxo-piperidine: 
In the foregoing reactions, each of R1, R2, R3, and Y are as defined above.
The 3-amino-2,6-dioxopiperidine can be obtained from the corresponding glutamic acid anhydride through conventional amidation or from the cyclization of appropriate glutamine derivatives.
The compounds in which Y is H2 alternatively can be obtained from a disubstituted benzoate intermediate according to the following reactions: 
in which R4 is CHO or CH2Br in the presence of an acid acceptor such as dimethylaminopyridine or triethylamine.
The disubstituted benzoate intermediates are known or can be obtained though conventional processes. For example, a lower alkyl ester of a 3,6-disubstituted ortho-toluic acid is brominated with N-bromosuccinimide under the influence of light to yield the lower alkyl 2-(bromomethyl)-3,6-disubstitutedbenzoate.
Alternatively, a dialdehyde is allowed to react with 2,6-dioxopiperidin-3-ammonium chloride to obtain the compounds of Formula I in which Y is H2: 
Finally, a dialdehyde is allowed to react with glutamine and the resulting 2-(1-oxo-isoindolin-2-yl)glutaric acid then cyclized to yield a 4,7-disubstituted 1-oxo-2-(2,6-dioxo-piperidin-3-yl)-isoindoline of Formula I in which Y is H2: 
The carbon atom to which R3 is bound in the compounds of Formula I constitutes a center of chirality, thereby giving rise to optical isomers: 
Both the racemates of these isomers and the individual isomers themselves, as well as diastereomers when a second chiral center is present, are within the scope of the present invention. The racemates can be used as such or can be separated into their individual isomers mechanically as by chromatography using a chiral absorbent. Alternatively, the individual isomers can be prepared in chiral form or separated chemically from a mixture by forming salts with a chiral acid or base, such as the individual enantiomers of 10-camphorsulfonic acid, camphoric acid, xcex1-bromocamphoric acid, methoxyacetic acid, tartaric acid, diacetyltartaric acid, malic acid, pyrrolidone-5-carboxylic acid, and the like, and then freeing one or both of the resolved bases, optionally repeating the process, so as obtain either or both substantially free of the other; i.e., in a form having an optical purity of  greater than 95%.
The present invention also pertains to the physiologically acceptable non-toxic acid addition salts of the compound of Formula I which contain a group capable of being protonated; e.g., amino. Such salts include those derived from organic and inorganic acids such as, without limitation, hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, methanesulphonic acid, acetic acid, tartaric acid, lactic acid, succinic acid, citric acid, malic acid, maleic acid, sorbic acid, aconitic acid, salicylic acid, phthalic acid, embonic acid, enanthic acid, and the like.
Particularly preferred compounds include 1,3-dioxo-2-(2,6-dioxopiperidin-3-yl)-4-methylisoindoline, 1,3-dioxo-2-(2,6-dioxopiperidin-3-yl)-4-ethylisoindoline, 1,3-dioxo-2-(2,6-dioxo-3-methylpiperidin-3-yl)-4-methylisoindoline, 1,3-dioxo-2-(2,6-dioxoopiperidin-3-yl)-4,7-dimethylisoindoline, 1-oxo-2-(2,6-dioxo-3-methylpiperidin-3-yl)-4-ethylisoindoline, 1-oxo-2-(2,6-dioxo-3-methylpiperidin-3-yl)-4-methylisoindoline, 1-oxo-2-(2,6-dioxo-3-methylpiperidin-3-yl)-7-ethylisoindoline, 1-oxo-2-(2,6-dioxo-3-methylpiperidin-3-yl)-7-methylisoindoline, 1-oxo-2-(2,6-dioxopiperidin-3-yl)-4-propylisoindoline, 1,3-dioxo-2-(2,6-dioxopiperidin-3-yl)-4-chloroisoindoline, 1,3-dioxo-2-(2,6-dioxopiperidin-3-yl)-4-carbamoylisoindoline, 1,3-dioxo-2-(2,6-dioxopiperidin-3-yl)-4-methoxyisoindoline, 1-oxo-2-(2,6-dioxoopiperidin-3-yl)-4,7-dimethylisoindoline, 1-oxo-2-(2,6-dioxoopiperidin-3-yl)-4-methyl-7-ethylisoindoline, and 1-oxo-2-(2,6-dioxopiperidin-3-yl)-4,7-diethoxyisoindoline. Of these, 1,3-dioxo-2-(2,6-dioxopiperidin-3-yl)-4-methylisoindoline, 1,3-dioxo-2-(2,6-dioxopiperidin-3-yl)-4,7-dimethylisoindoline, 1-oxo-2-(2,6-dioxopiperidin-3-yl)-4-methylisoindoline, and 1 oxo-2-(2,6-dioxopiperidin-3-yl)-4,7-dimethylisoindoline are particularly preferred.
Oral dosage forms include tablets, capsules, dragees, and similar shaped, compressed pharmaceutical forms containing from 1 to 100 mg of drug per unit dosage. Isotonic saline solutions containing from 20 to 100 mg/mL can be used for parenteral administration which includes intramuscular, intrathecal, intravenous and intra-arterial routes of administration. Rectal administration can be effected through the use of suppositories formulated from conventional carriers such as cocoa butter.
Pharmaceutical compositions thus comprise one or more compounds of Formulas I associated with at least one pharmaceutically acceptable carrier, diluent or excipient. In preparing such compositions, the active ingredients are usually mixed with or diluted by an excipient or enclosed within such a carrier which can be in the form of a capsule or sachet. When the excipient serves as a diluent, it may be a solid, semi-solid, or liquid material which acts as a vehicle, carrier, or medium for the active ingredient. Thus, the compositions can be in the form of tablets, pills, powders, elixirs, suspensions, emulsions, solutions, syrups, soft and hard gelatin capsules, suppositories, sterile injectable solutions and sterile packaged powders. Examples of suitable excipients include lactose, dextrose, sucrose, sorbitol, mannitol, starch, gum acacia, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidinone, cellulose, water, syrup, and methyl cellulose, the formulations can additionally include lubricating agents such as talc, magnesium stearate and mineral oil, wetting agents, emulsifying and suspending agents, preserving agents such as methyl- and propylhydroxybenzoates, sweetening agents or flavoring agents.
The compositions preferably are formulated in unit dosage form, meaning physically discrete units suitable as a unitary dosage, or a predetermined fraction of a unitary dose to be administered in a single or multiple dosage regimen to human subjects and other mammals, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect in association with a suitable pharmaceutical excipient. The compositions can be formulated so as to provide an immediate, sustained or delayed release of active ingredient after administration to the patient by employing procedures well known in the art.
Enzyme-linked immunosorbent assays for TNFxcex1 can be performed in a conventional manner. PBMC is isolated from normal donors by Ficoll-Hypaque density centrifugation. Cells are cultured in RPMI supplemented with 10% AB+ serum, 2mM L-glutamine, 100 U/mL penicillin, and 100 mg/mL streptomycin. Drugs are dissolved in dimethylsulfoxide (Sigma Chemical) and further dilutions are done in supplemented RPMI. The final dimethylsulfoxide concentration in the presence or absence of drug in the PBMC suspensions is 0.25 wt %. Drugs are assayed at half-log dilutions starting at 50 mg/mL. Drugs are added to PBMC (106 cells/mL) in 96 wells plates one hour before the addition of LPS. PBMC (106 cells/mL) in the presence or absence of drug are stimulated by treatment with 1 mg/mL of LPS from Salmonella minnesota R595 (List Biological Labs, Campbell, Calif.). Cells are then incubated at 37xc2x0 C. for 18-20 hours. Supernatants are harvested and assayed immediately for TNFxcex1 levels or kept frozen at xe2x88x9270xc2x0 C. (for not more than 4 days) until assayed. The concentration of TNFxcex1 in the supernatant is determined by human TNFxcex1 ELISA kits (ENDOGEN, Boston, Mass.) according to the manufacturer""s directions.